it to Sir Ray Lankester to
have made it clear that these two types of brain are, as it were, on
different tacks of evolution, and should not be directly pitted against
one another. The "little-brain" type makes for a climax in the ant,
where instinctive behaviour reaches a high degree of perfection; the
"big-brain" type reaches its climax in horse and dog, in elephant and
monkey. The particular interest that attaches to the behaviour of birds
is in the combination of a good deal of instinct with a great deal of
intelligent learning. This is well illustrated when birds make a nest
out of new materials or in some quite novel situation. It is clearly
seen when birds turn to some new kind of food, like the Kea parrot,
which attacks the sheep in New Zealand.

Some young woodpeckers are quite clever in opening fir cones to get at
the seeds, and this might be hastily referred to a well-defined
hereditary capacity. But the facts are that the parents bring their
young ones first the seeds themselves, then partly opened cones, and
then intact ones. There is an educative process, and so it is in scores
of cases.

Using their Wits

When the Greek eagle lifts the Greek tortoise in its talons, and lets it
fall from a height so that the strong carapace is broken and the flesh
exposed, it is making intelligent use of an expedient. Whether it
discovered the expedient by experimenting, as is possible, or by chance,
as is more likely, it uses it intelligently. In the same way
herring-gulls lift sea-urchins and clams in their bills, and let them
fall on the rocks so that the shells are broken. In the same way rooks
deal with freshwater mussels.

The Thrush's Anvil

A very instructive case is the behaviour of the song-thrush when it
takes a wood-snail in its beak and hammers it against a stone, its
so-called anvil. To a young thrush, which she had brought up by hand,
Miss Frances Pitt offered some wood-snails, but it took no interest in
them until one put out its head and began to move about. The bird then
pecked at the snail's horns, but was evidently puzzled when the creature
retreated within the shelter of the shell. This happened over and over
again, the thrush's inquisitive interest increasing day by day. It
pecked at the shell and even picked it up by the lip, but no real
progress was made till the sixth day, when the thrush seized the snail
and beat it on the ground as it would a big worm. On the same day it
picked up a s